Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

There are no annotations, so the description carries the full burden. It discloses that the title is 'discarded after the call', which suggests no state retention, but it does not state what the tool returns, whether it makes a network request, or what happens for invalid or missing titles.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is only two short sentences, with the primary action front-loaded. The second sentence adds a relevant behavioral detail without unnecessary verbosity.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no annotations, no output schema, and an input schema full of seemingly unrelated optional parameters, the description is far too thin. It does not explain return values, which parameter carries the title, or how to distinguish this tool from related sibling tools, so an agent lacks essential information to use it reliably.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The input schema provides descriptions for seven parameters, but none of them is a Wikipedia title and the description gives no hint which parameter to use. The tool's stated purpose requires a 'title' input, yet no such field exists in the schema, making correct invocation effectively impossible from the definition.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific verb and resource: 'Check whether a Wikipedia title exists.' This makes the tool's basic purpose clear. It does not explicitly differentiate itself from siblings, but the name and one-line purpose are enough to identify what it does.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

There is no guidance about when to use this tool instead of alternatives such as web-fetch, normalize-url, or citation. The description only implies usage through the verb 'check', but does not state prerequisites, exclusions, or context in which it is preferred.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.